Four photons sensitivity heterodyne detection of submillimeter radiation with superconducting tunnel junctions

Abstract

Domaine Universitaire, 38406 St. M a r t i n dHeres, FranceAbstracfiAn ultra low noise SIS receiver has been prepared for radio astronomy. The minimum doub\e sideband receiver noise temperature is about 30 K which corresponds to 2 A& or an equivalent number of 4 photons of noise. The minimum measured double sideband mixer noise temperature is about 10 K which corresponds to 0.6 lolk or approximately to 1 photon of noise. The fixed tuned SIS mixer operates in the 290-370 GHz fkequency range. The submicron niobium junctions were fabricated using photoresist lines for junction definition. The receiver has been used at the 30 m IRAM radio telescope in Spain in winter 1994. Telescope system noise temperature of 500 K single sideband has been achieved when the sky opacity was about 0.17.

Low-Noise Sis Receivers for New Radio-Astronomy Projects

“…The mixers on the basis of the superconductorinsulator-superconductor (SIS) tunnel junctions are definitely the best input devices for coherent receivers at the frequencies in the range from 0.1 to 1.2 THz since their noise temperature is restricted only by the quantum limit. At present, the heterodyne SIS receivers are used as standard units in the majority of both ground-based and space-borne radio telescopes all over the world [1][2][3][4][5][6][7][8][9][10]. In particular, the SIS receivers are successfully operated in all high-frequency ranges of the greatest contemporary radio-astronomy project, namely, the multielement interferometer ALMA (Atacama Large Millimeter/Submillimeter Array).…”

Параметры Туннельного Барьера Сверхпроводниковых Структур На Основе Ниобия

“…Смесители на основе туннельных переходов сверхпроводник-изолятор-сверхпроводник (СИС) являются наиболее чувствительными входными элементами для когерентных приемников на частотах от 0.1 до 1.2 THz, их шумовая температура ограничена только квантовым пределом. В настоящее время СИС-приемники используются в качестве штатных устройств на большинстве как наземных, так и космических радиотелескопов во всем мире [1][2][3][4][5][6]. Для повышения рабочей частоты сверхпроводящих схем, основанных на СИС-переходах, и расширения их полосы, необходимы туннельные переходы с высокой плотностью тока.…”

Superconducting Receivers for Space, Balloon, and Ground-Based Sub-Terahertz Radio Telescopes

“…In [23], the method of determining the noise temperature of a SIS mixer in quantum mode with allowance for the Heisenberg uncertainty principle is substantiated, and it is shown that the noise temperature of a SIS mixer in a two-band regime is theoretically limited only by the quantum value hf /(2k B ) (here, h is the Planck constant, f is the frequency of the received radiation, and k B is the Boltzmann constant). That is exactly why the heterodyne SIS receivers are used in the majority of both ground-based and spaceborne radio telescopes [24][25][26][27][28][29][30][31][32].…”

“…Exceptionally sensitive mixers of the range in the vicinity of 250 GHz were developed already at the end of the last century (their noise temperature was 10-15 K) [25,33]. However, mechanical adjustment of the waveguide circuit breaker was required to obtain extremely low noise temperatures, which limited their wide application.…”